Snowcover interaction with
climate, topography & vegetation
in mountain catchments
DANNY MARKS
Northwest Watershed Research Center
USDA-Agricultural Research Service
Boise, Idaho
USA
RCEW (239 km2):
• 32 climate stations
• 36 precipitation stations
• 5 EC systems
• 14 weirs (nested)
• 6 soil microclimate stations
• 4 hill-slope hydrology sites
• 4 instrumented catchments
• 3 instrumented headwater
basins:
USC (0.25 km2, 186m relief)
ephemeral, groundwater dominated,
annual precipitation 300-500mm
RME (0.38 km2, 116m relief)
perennial, surface water dominated,
annual precipitation 750-1000mm
Johnston Draw (1.8 km2, 380m relief)
ephemeral, rain-snow boundary,
annual precipitation 500-600mm
Climate Trends from 45 Years of
Monitoring at Reynolds Creek
Experimental Watershed
DANNY MARKS
PhD project, ANURAG NAYAK
(Utah State University)
Northwest Watershed Research Center
USDA-Agricultural Research Service
Boise, Idaho
USA
Annual Precipitation
1800
1600
Elevation: 2097 m (176)
176
Elevation: 1652 m (127)
127
1400
1200
1000
800
600
400
200
0
600
400
300
200
100
0
500
Elevation: 1207 m (076)
076
400
300
200
100
2005
2003
2001
1999
1997
1995
1993
1991
1989
1987
1985
1983
1981
1979
1977
1975
1973
1971
1969
1967
1965
0
1963
No
Significant
Trend
500
Annual Stream Discharge
0.5
RME (2023 m, Drainage: 39 ha)
0.4
0.3
0.2
Tollgate (1410 m, Drainage: 5,468 ha)
30
25
20
15
10
5
0
50
45
Outlet (1099 m, Drainage: 23,828 ha)
40
35
30
25
20
15
10
5
2004
2002
2000
1998
1996
1994
1992
1990
1988
1986
1984
1982
1980
1978
1976
1974
1972
1970
1968
0
1966
Trend
0.0
35
1964
No Significant
Streamflow (km 3)
0.1
% Annual Stream Discharge, by Month
March, April, May & June (78-95% of Annual Flow)
70
Headwater Catchment:
March +3%
April +14%
May
------June
-11%
RME (2023 m, Drainage: 39 ha)
60
Summer Flow:
Reduced from
9% to 3%
50
40
30
67% Reduction
20
10
0
70
Mid-Elevation Drainage:
March +1%
April +12%
May
+1%
June
-5%
60
50
Tollgate (1410 m, Drainage: 5,468 ha)
MAR
Summer Flow:
Reduced from
21% to 10%
APR
MAY
JUN
40
30
52% Reduction
20
10
0
70
Basin Outlet:
March ------April
+4%
May
+12%
June
-1%
Outlet (1099 m, Drainage: 23,828 ha)
60
Summer Flow:
Reduced from
27% to 12%
50
40
30
20
56% Reduction
10
0
1961
1966
1971
1976
1981
1986
1991
1996
2001
2006
+ 2.5:
-0.6 to +1.9
+ 2.4:
+7.9 to +10.3
+ 2.7:
+2.5 to +5.2
+ 0.9:
+11.8 to +12.7
+ 1.4:
+1.7 to +3.1
+ 0.9:
15.4 to 16.3
Snow: -16%:
80% to 62%
Snow: -17%:
55% to 38%
Snow: -22%:
41% to 19%
Still Snow
Dominated
Now Rain
Dominated
Almost Never
Snows
• Annual precipitation & discharge are unchanged
– However, early spring flows are increased
– Summer flows are significantly reduced
• Climate is warming
– All temperatures have increased
– Minimum temperatures increased the most
• More precipitation falls as rain
– Smaller change at high elevation
– Large change at low elevation
• Strong elevation effect
– Effects availability of water in summer
– More area at lower elevation
– Increase in winter ROS events
Reynolds Creek Experimental Watershed
Tollgate Basin
Area: 54.6 km2
Elev: 1410 - 2241 m
Scaling up to Tollgate
Snow & Hydrologic Modeling:
Simulation of terrain and forest
shelter effects on wind fields,
patterns of snow redistribution,
snowmelt and runoff
DANNY MARKS
PhD project, ADAM WINSTRAL
(University of Reading, UK)
Northwest Watershed Research Center
USDA-Agricultural Research Service
Boise, Idaho
USA
Snow Redistribution and Drifting
Drifts and Forest Cover, RCEW
Forest Canopy- Snowcover Interaction
Reynolds Mountain East Study Catchment
(0.38 km2, 118 m relief)
The Ridge Site
The Grove Site
The Grove Site
Four Snow Seasons Selected for Simulation
1986, 1987, 1989 for SCA Data
1997 for ROS Event
I.
Verify Simulated Snow Distributions
* Time-series AP
II. Evaluate Terrain & Vegetation Shelter Effects on
* Simulated Snow Cover Energy Balance
* Snow Melt
* Runoff
Modeled and Observed SWE (Point Comparison)
1986 Simulated Snow Distribution
Aerial
Photos
Modeled
SWE
1986 Simulated Snow Distribution
Aerial
Photos
Modeled SWE:
spatially constant
wind and
precipitation inputs
1986 Simulated Surface Water Inputs
Spatially Distributed Wind
and Precipitation Inputs
Spatially Constant Wind
and Precipitation Inputs
1987 Simulated Snow Distribution
Aerial
Photos
Modeled
SWE
1987 Simulated Surface Water Inputs
1989 Simulated Snow Distribution
Aerial
Photos
Modeled
SWE
1989 Simulated Surface Water Inputs
1997 Simulated Surface Water Inputs and SWE
Mid-winter ROS: Sensible + Latent Heat dominated
Early spring wind event: Sensible Heat dominated
Typical spring melt event: Radiation dominated
Simulated
Daily SWE
1986 Snow Season
View movie at http://www.usask.ca/ip3/download/presentations/swe_movie.avi
Boise River Basin (2150 km2)
1998 Water Year
DANNY MARKS and DAVID GAREN*
* National Water and Climate Center
USDA-Natural Resources Conservation Service
Portland, Oregon, USA
•
•
•
•
Large Area Climate Data Distribution
Canopy Corrections
Satellite Derived Snow Covered Area for Verification
Streamflow Simulation
9-Oct
0
700
600
500
Observed
Simulated
400
300
200
100
0
26-Jun
800
6-Jun
900
800
17-May
900
27-Apr
1000
900
7-Apr
Jackson Peak (2155 m)
18-Mar
1000
26-Feb
1000
6-Feb
26-Jun
6-Jun
17-May
27-Apr
7-Apr
18-Mar
26-Feb
6-Feb
17-Jan
Mores Creek Summit (1859 m)
17-Jan
200
8-Dec
300
28-Dec
400
28-Dec
Observed
Simulated
Snow Water Equivalent (mm)
600
18-Nov
800
8-Dec
800
18-Nov
900
800
29-Oct
500
9-Oct
26-Jun
6-Jun
17-May
27-Apr
7-Apr
18-Mar
26-Feb
6-Feb
17-Jan
700
Snow Water Equivalent (mm)
8-Dec
1000
900
9-Oct
100
28-Dec
1000
900
29-Oct
200
26-Jun
300
6-Jun
Simulated
17-May
400
27-Apr
Observed
7-Apr
600
18-Mar
Graham Guard Station (1734 m)
26-Feb
700
18-Nov
200
29-Oct
1000
Snow Water Equivalent (mm)
300
6-Feb
500
9-Oct
26-Jun
6-Jun
17-May
27-Apr
7-Apr
18-Mar
400
17-Jan
6-Feb
26-Feb
Atlanta Town (1649 m)
28-Dec
0
17-Jan
Simulated
8-Dec
0
8-Dec
Observed
18-Nov
100
0
28-Dec
500
29-Oct
100
18-Nov
600
Snow Water Equivalent (mm)
9-Oct
100
29-Oct
Snow Water Equivalent (mm)
700
9-Oct
26-Jun
6-Jun
17-May
27-Apr
7-Apr
18-Mar
26-Feb
6-Feb
17-Jan
28-Dec
8-Dec
18-Nov
29-Oct
Snow Water Equivalent (mm)
Boise River Snow Water Equivalent
Water Year 1998
Atlanta Summit (2310 m)
700
600
500
400
Observed
Simulated
300
200
Trinity Mountain (2368 m)
800
700
600
500
400
Observed
Simulated
300
200
100
0
Simulated and Satellite
Snow Covered Area (SCA)
Boise River Basin, Water Year 1998
100
90
Snow Covered Area (%)
80
70
60
Satellite
Simulated
50
40
30
20
10
0
1-Apr
16-Apr
1-May
16-May 31-May
15-Jun
30-Jun
15-Jul
Boise River Simulated Snow Water Equivalent
and Satellite Snow Covered Area (SCA)
21 April 1998
Boise River Simulated Snow Water Equivalent
and Satellite Snow Covered Area (SCA)
7 May 1998
Boise River Simulated Snow Water Equivalent and
Satellite Snow Covered Area (SCA)
21 May 1998
Boise River Simulated Snow Water Equivalent
and Satellite Snow Covered Area (SCA)
29 June 1998
Boise River Streamflow Simulation
Water Year 1998
Comparing sensible and
latent heat fluxes over snow
along a North American
Cordilleran Transect
DANNY MARKS & John Pomeroy
Students:
Michele Reba (U of I)
Warren Helgason (U of S)
Dan Bewley (U of Wales)
Northwest Watershed Research Center
USDA-Agricultural Research Service
Boise, Idaho
USA
GAPP North American Cordilleran Transect
WCRB
WCRB
WCRB: Wolf Creek
MCRB
MCRB
Research Basin,
Yukon Territory, Canada
MCRB: Marmot Creek
RCEW
LSOS
Research Basin
Alberta, Canada
RCEW
RCEW: Reynolds Creek
Experimental Watershed,
Idaho, USA
LSOS: Local Scale
Observation Site
Colorado, USA
LSOS
RME Study Site
Reynolds Mountain East
The Grove
The Protected Site
The Ridge
The Exposed Site
Exposed Site
Protected Site
WY 2005 Monthly EC-Measured H & LvE
Over Sage and Below Aspen:
WY 2005 Monthly EC-Measured CO2 & ET
Over Sage and Below Aspen:
Preliminary Conclusions
• First full-year measurements of evaporation/transpiration
– ~33% (211 mm) of 2005 deposition (630 mm) lost to ET
over sage
– ~10% (90 mm) of 2005 deposition (879 mm) lost to ET
below aspen
• First measurements of Carbon flux
– Sage site close to balance, but lost carbon to atmosphere
– Below aspen site took carbon from the atmosphere
– Critical to get Above Aspen Data
• Data only for 2005 water year; add 2004 & 2006 data
Scale effects on snowcover
accumulation and melt modelling:
Determining the minimum complexity required to capture
essential features of snowmelt over large regions with
complex terrain
DANNY MARKS
PhD project, ADAM WINSTRAL
(University of Reading, UK)
Northwest Watershed Research Center
USDA-Agricultural Research Service
Boise, Idaho
USA
Scaling Issues
• Distributing Forcing Data Over Large Areas
• Orography (Pacific NW & BC - ROS events)
• Mixed phase precipitation events: Rain vs Snow
• Dew point temperature as an indicator of phase
• Terrain & canopy-induced variability
• Linkages between forcing & energy state
• Measurement & Validation
Johnston Draw Study Catchment
(1.8 km2 , 380 m relief)
Preliminary Conclusions
• Dew Point Temperature is a reliable predictor of
precipitation phase.
• Need second year of data, and additional events for
validation
• Need data from additional sites (Klamath River basin,
Oregon; BC?)
• Summer Precipitation (Kananaskis, Wolf Creek)
A Scalable Shading Model for
Radiation at the Forest Floor,
using LiDAR-derived Canopy
Parameters
RICHARD ESSERY
(University of Wales, Aberystwyth)
DANNY MARKS
(USDA-ARS Northwest Watershed Research Center)
See: Essery, Bunting, Hardy, Link, Marks, Melloh, Pomeroy, Rowlands and Rutter,
2007, in review, Journal of Hydrometeorology;
Pomeroy, Rowlands, Hardy, Link, Marks, Essery, Sicart and Ellis,
2007, in review, Journal of Hydrometeorology
Geometric shading model
dc
l
+
+
θ
h
cbh
Tall Shrubs, Wolf Creek
Marmot Creek level forest
Solar Radiation to Snow beneath Shrubs and Trees
1000
400
300
2
SW(W/m )
2
SW (W/m )
800
600
400
200
200
100
0
0
123
124
125
74
D a y (2 0 0 3 )
75
Day (2005)
See: Pomeroy, et al., in review, 2007, Journal of Hydrometeorology;
Bewley et al., 2007, in press, Arctic, Antarctic and Alpine Research;
Link, Marks and Hardy, 2004, Hydrological Processes
76
Inventory map
LiDAR + tree map
100 m
Stand Scale Modelling of Solar Radiation
Simulated sky view
Simulated sky view
Clear
Overcast
600
Measured
500
2
SW (W/m )
Modelled
400
300
200
100
0
84
85
Day (2003)
Essery et al. (2007). In review for Journal of Hydrometeorology.
86
Fine Scale Modelling of Sub-alpine Solar Radiation
Essery et al. (2007). In review for Journal of Hydrometeorology.
LiDAR Forest CSM & DEM
Characterization
Pomeroy, et al., in review, 2007, Journal of Hydrometeorology;
Essery et al. (2007). In review for Journal of Hydrometeorology
Sky view
From hemispherical
photographs
From LiDAR shading
model
Essery et al. (2007). In review for Journal of Hydrometeorology
The Longwave Radiation Problem:
Hot Canopy and Trunks Increase Forest Longwave
Radiation
14:20
11.40
17.00
JD86 Cloudy
JD87 Sunny
Temperature (TC) C
50
CLPX LSOS Open Canopy IOP1
40
Canopy North
30
Trunk
Snow Surface
20
Canopy South
10
0
-10
-20
-30
50
50.5
51
51.5
52
52.5
Julian Day 2002
53
53.5
Pomeroy, Marks, Ellis, et al., 2007, in prep, Hydrological Processes
54